JP2023169576A - Active energy ray-curable offset ink, printed material using the same, and method for producing printed material - Google Patents

Abstract

To provide an active energy ray-curable offset ink that suppresses the gelling of the ink and exhibits excellent curability and adhesion even when used in ozone-less metal halide lamps with no ozone emission, light-emitting diodes and UV-LED lamps as well as the conventional metal halide lamps and high-pressure mercury lamps, and to provide a printed material using the ink, and a method for producing the printed material.SOLUTION: An active energy ray-curable offset print ink contains a photopolymerization initiator, and a compound with an ethylenic double bond. A gelation speed until the torque of the ink increases by 20%, according to a viscosimetric assay method, ranges from 750 seconds to 1,000 seconds.SELECTED DRAWING: None

Description

The present invention provides an ultraviolet irradiation device that does not easily cause ink to gel, and that does not generate ozone using a light source that uses ozone cut or infrared filters for metal halide lamps, high-pressure mercury lamps, electrodeless metal halide lamps, etc. The present invention relates to an active energy ray-curable offset ink that has both excellent curing properties and adhesion properties even with an ultraviolet irradiation device using a diode or UV-LED lamp. Furthermore, the present invention relates to a printed matter using the ink and a method for manufacturing the printed matter.

Since active energy ray-curable ink is solvent-free and instantly cures and dries, it is environmentally friendly, has excellent printing workability, and can produce high-quality printed matter. Planographic printing that uses waterless planographic printing that does not use dampening water), letterpress printing, intaglio printing, stencil printing, and printing materials after transferring the ink on these plates to an intermediate transfer material such as a blanket. It is used as an ink in various printing methods that combine transfer (offset) printing methods, such as form prints, various book prints, various packaging prints such as carton paper, various plastic prints, stickers, label prints, It is applied to various printed matter such as fine art printed matter, metal printed matter (art printed matter, beverage can printed matter, food printed matter such as canned food). In particular, active energy ray-curable offset printing ink, which combines planographic printing and offset printing, is widely used in various fields such as book printing, art printing, sticker/label printing, business form printing, and package printing for food packaging such as toys and paper cartons. It is used.
Ultraviolet curable offset ink that cures under active energy ray conditions has the convenience of instant drying and is suitable for various book printing, art printing, sticker/label printing, business form printing, and package printing for food packaging such as toys and paper cartons. It is widely used in fields such as
In addition to conventional light sources such as mercury lamps and metal halide lamps, active energy ray-curable inks use ozone-less metal halide lamps that emit ultraviolet light in the wavelength range of 230 to 420 nm, as well as light sources that emit light in the wavelength range of 230 to 420 nm. Various types of light sources have been used in recent years, such as light emitting diodes (UV-LEDs) that emit ultraviolet light with a peak wavelength in the range of 350 to 420 nm, and it is necessary to use photopolymerization initiators with different absorption wavelengths to match the wavelength range of the various light sources. Inventions have been made that combine multiple methods (Patent Documents 1 to 3).
On the other hand, although active energy ray-curable inks are generally stored at room temperature, they may gel during storage. Compared to ultraviolet curing inks using light sources such as mercury lamps and metal halide lamps, light sources that use ozone-less metal halide lamps that emit ultraviolet rays in the range of 230 to 420 nm, and those with peak emission wavelengths in the range of 350 to 420 nm, Ultraviolet curing inks such as UV-LEDs, which generate ultraviolet rays, tend to gel more easily. This is due to the fact that the output and emission wavelength of the UV lamp are limited, and in order to compensate for this, a large amount of photopolymerization initiator in the ultraviolet curable ink must be used.
At present, it cannot be said that, while suppressing the gelation of the ink, sufficient curability and adhesion, which are the basic characteristics of active energy ray-curable inks, can be achieved against these light sources.

WO2009/008226 publication Japanese Patent Application Publication No. 2011-94117 Japanese Patent Application Publication No. 2012-214782

The objective of the present invention is to suppress ink gelation, and to achieve excellent curing and adhesion not only with conventional metal halide lamps and high-pressure mercury lamps, but also with ozone-less metal halide lamps that do not generate ozone, light-emitting diodes, and UV-LED lamps. An object of the present invention is to provide an active energy ray-curable offset ink that is characterized by having both properties. Another object of the present invention is to provide a printed matter using the ink and a method for manufacturing the printed matter.

As a result of extensive research to solve the above problems, the present inventors have developed an active energy ray-curable offset printing ink containing a photopolymerization initiator and a compound having an ethylenic double bond,
By setting the gelation rate of the ink within a specific range according to the above ink viscosity measurement method, an active energy ray-curable offset ink that is difficult to gel and has both excellent curability and adhesion can be obtained. This discovery led to the completion of the present invention.

That is, the present invention is an active energy ray-curable offset printing ink containing a photopolymerization initiator and a compound having an ethylenic double bond,
Provided is an active energy ray-curable offset printing ink, characterized in that the gelation rate until the torque increases by 20% according to the ink viscosity measurement method is in the range of 750 seconds to 1000 seconds.

Further, the present invention provides that the active energy ray-curable offset printing ink comprises:
(1) a photopolymerization initiator (1) that is an α-aminoalkylphenone compound and/or an acylphosphine oxide compound;
(2) a photopolymerization initiator (2) which is a benzophenone compound, a thioxanthone compound, and/or a ketocoumarin compound;
(3) a stabilizer that is a dimethyldithiocarbamate copper complex;
(4) An active energy ray-curable offset printing ink containing a compound having an ethylenic double bond is provided.

Further, the present invention provides that the α-aminoalkylphenone compound is 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-dimethylamino-2-(4-methyl-benzyl )-1-(4-morpholin-4-yl-phenyl)-butan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2- Benzyl-2-dimethylamino-1-(4-piperidinylphenyl)-1-butanone, 1-(biphenyl-4-yl)-2-methyl-2-morpholinopropan-1-one, 1-(4 -methoxyphenyl)-2-methyl-2-morpholin-4-yl-propan-1-one, polyethylene glycol (200) di(β-4[4-(2-dimethylamino-2-benzyl)butanonylphenyl) ] An active energy ray-curable offset printing ink which is piperazine propionate is provided.

The present invention also provides an active energy ray-curable offset printing ink in which the acylphosphine oxide compound is a compound represented by general formula (1).

In general formula (1),
Y ₁ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a structural moiety represented by general formula (2),
Y ₂ is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a (poly)alkoxyalkyl group having 1 to 6 carbon atoms (the alkoxyalkyl group is an alkyl group having 1 to 6 carbon atoms). represents a structural moiety represented by alkoxyalkyl group), phenyl group, or general formula (3),
Y ₃ represents a phenyl group or a group represented by general formula (2),

In general formula (3), Y ₁₁ each independently represents the same group as Y ₁ in general formula (1),
Y ₃₃ in general formula (3) each independently represents the same group as Y ₃ in general formula (1),
R ₁₄ and R ₁₅ in general formula (3) each independently represent an alkylene group having 1 to 6 carbon atoms or a (poly)oxyalkylene group having 1 to 6 carbon atoms,
R ₁ to R ₁₃ in the general formulas (1), (2), and (3) each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

Further, the present invention provides that the benzophenone compound is 4,4'-bis-(dimethylamino)benzophenone, 4,4'-bis-(diethylamino)benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 4-methylbenzophenone Provided is an active energy ray-curable offset printing ink that is at least one selected from the group consisting of:

The present invention also provides an active energy ray-curable offset printing ink containing the dimethyldithiocarbamate copper complex and nitrosamine compound as stabilizers in an amount of 0.01 to 0.30% by mass based on the total amount of the ink.

The present invention also provides an active energy ray-curable offset printing ink, wherein the compound having an ethylenic double bond is a compound having two or more ethylenic double bonds.

The present invention also provides a method for producing printed matter, comprising the steps of printing the active energy ray-curable offset printing ink on a printing substrate, and curing the ink printed with the active energy ray. do.

The present invention also provides a method for producing printed matter, wherein the printing substrate is paper having a moisture content of 5 to 300 grams per square meter.

The present invention suppresses ink gelation and provides excellent curing and adhesion not only for conventional metal halide lamps and high-pressure mercury lamps, but also for ozone-less metal halide lamps that do not generate ozone, light emitting diodes, and UV-LED lamps. It is possible to provide an active energy ray-curable offset ink that has the following characteristics. Furthermore, it is possible to provide a printed matter using the ink and a method for manufacturing the printed matter.

The active energy ray curable offset printing ink of the present invention is an active energy ray curable offset printing ink containing a photopolymerization initiator and a compound having an ethylenic double bond,
The desired effect of the present invention is achieved when the gelation rate until the torque increases by 20% according to the ink viscosity measurement method is in the range of 750 seconds to 1000 seconds.

Active energy ray-curable inks are generally stored at room temperature, but may gel during storage. Compared to ultraviolet curing inks using light sources such as mercury lamps and metal halide lamps, light sources that use ozone-less metal halide lamps that emit ultraviolet rays in the range of 230 to 420 nm, and those with peak emission wavelengths in the range of 350 to 420 nm, Ultraviolet curing inks such as UV-LEDs, which generate ultraviolet rays, tend to gel more easily. This is due to the fact that the output and emission wavelength of the UV lamp are limited, and in order to compensate for this, a large amount of photopolymerization initiator in the ultraviolet curable ink must be used.
Therefore, an active energy ray-curable offset ink that is as difficult to gel as possible is desired.
In the active energy ray-curable offset ink of the present invention, by raising the temperature while stirring the ink under certain conditions, the gelation rate is regarded as the time (in seconds) from the start of stirring until the torque increases by 20%. It is essential that the gelation rate is in the range of 750 seconds to 1000 seconds. If the gelation speed is in the range of 750 seconds to 1000 seconds, gelation tends to be difficult, and if it exceeds 1000 seconds, the ink itself tends to solidify.
In the present invention, the gelation rate was measured using an automatic curing time measuring device "Madoka" manufactured by Cyber Co., Ltd.
The amount of active energy ray-curable offset ink used for one measurement was 0.2 ml, and the stirring conditions were a rotation speed of 300 rpm and a revolution speed of 120 rpm.
After confirming that the temperature was stabilized at 80°C for 5 minutes, the temperature was increased to 250°C in 1000 seconds.
Further, the gap value between the bottom of the ink container and the tip of the stirrer was set to 0.1 mm.

Furthermore, the active energy ray-curable offset printing ink of the present invention contains the following (1) to (4).
(1) a photopolymerization initiator (1) that is an α-aminoalkylphenone compound and/or an acylphosphine oxide compound;
(2) a photopolymerization initiator (2) which is a benzophenone compound, a thioxanthone compound, and/or a ketocoumarin compound;
(3) a stabilizer that is a dimethyldithiocarbamate copper complex;
(4) A compound having an ethylenic double bond.

The α-aminoalkylphenone compounds include 2-(dimethylamino)-2-methyl-1-[4-(4-morpholinyl)phenyl]-3-phenyl-1-propanone, 1-butanone, 2-(dimethyl amino)-1-[4-(4-morpholinyl)phenyl]-2-(phenylmethyl)-, (2S)-, 2-(dimethylamino)-2-methyl-3-(4-methylphenyl)-1 -[4-(4-morpholinyl)phenyl]-1-propanone, 2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-2-(phenylmethyl)-1-pentanone, 2-( dimethylamino)-2-[(4-ethylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2-(dimethylamino)-2-[(4-hydroxyphenyl)methyl ]-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2-[(4-butylphenyl)methyl]-2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl] -1-butanone, 1-butanone, 2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-2-[(4-propylphenyl)methyl]-, 2-(dimethylamino)-1 -[4-(4-morpholinyl)phenyl]-2-phenyl-1-butanone, 3-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-3-(phenylmethyl)-2-pentanone , 2-(dimethylamino)-2-ethyl-1-[4-(4-morpholinyl)phenyl]-4-phenyl-1-butanone, 3-(dimethylamino)-1-[4-(4-morpholinyl) phenyl]-3-phenyl-2-butanone, 1-(4-mercaptophenyl)-2-methyl-2-(4-morpholinyl)-1-propanone, 1-[4-(ethylthio)phenyl]-2-methyl -2-(4-morpholinyl)-1-propanone, dimethyl[4-[2-methyl-2-(4-morpholinyl)-1-oxopropyl]phenyl]sulfonium, 2-methyl-1-[4-[( 1-Methylethyl)thio]phenyl]-2-(4-morpholinyl)-1-propanone, ethylmethyl[4-[2-methyl-2-(4-morpholinyl)-1-oxopropyl]phenyl]sulfonium, 2 -Benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl )-butan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-piperidinyl phenyl)-1-butanone, 1-(biphenyl-4-yl)-2-methyl-2-morpholinopropan-1-one, 1-(4-methoxyphenyl)-2-methyl-2-morpholine-4 -yl-propan-1-one, polyethylene glycol (200) di(β-4[4-(2-dimethylamino-2-benzyl)butanonylphenyl]piperazine propionate, etc.).
In particular, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholine-4- yl-phenyl)-butan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4- piperidinylphenyl)-1-butanone, 1-(biphenyl-4-yl)-2-methyl-2-morpholinopropan-1-one, 1-(4-methoxyphenyl)-2-methyl-2-morpho Lin-4-yl-propan-1-one, polyethylene glycol (200) di(β-4[4-(2-dimethylamino-2-benzyl)butanonylphenyl]piperazine propionate is preferred.

It is preferable that the acylphosphine oxide compound is a compound represented by general formula (1).

In general formula (1),
Y ₁ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a structural moiety represented by general formula (2),
Y ₂ is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a (poly)alkoxyalkyl group having 1 to 6 carbon atoms (the alkoxyalkyl group is an alkyl group having 1 to 6 carbon atoms). represents a structural moiety represented by alkoxyalkyl group), phenyl group, or general formula (3),
Y ₃ represents a phenyl group or a group represented by general formula (2),

In particular, in general formula (1), R ₁ , R ₂ and R ₄ are methyl groups, R ₃ and Y ₁ are hydrogen, Y ₂ is ethyl group, and Y ₃ is phenyl group (ethylphenyl (2,4,6- Trimethylbenzoyl)phosphinate is preferred, and a commercially available product is TPO-L (#CAS 84434-11-7, manufactured by SARTOMER).

Furthermore, in general formula (1), R ₁ , R ₂ and R ₄ are methyl groups, R ₃ is a hydrogen atom, Y ₂ is a polyalkoxymethyl group having 2 carbon atoms, and Y ₃ is represented by general formula (2). It is preferable that R ₆ , R ₇ and R ₉ are methyl groups and R ₅ and R ₈ are hydrogen, and a commercially available product is Omnirad 820 (manufactured by IGM Resins B.V.). I can list them.

Furthermore, in the general formula (1), R ₁ , R ₂ and R ₄ are methyl groups, R ₃ is a hydrogen atom, Y ₁ is a structural moiety represented by the general formula (2), and R ₅ to R ₉ Ethyl (3-benzoyl-2,4,6-trimethylbenzoyl)(phenyl)phosphinate in which is a hydrogen atom, Y ₂ is an ethyl group, and Y ₃ is a phenyl group is preferable, and a commercially available product is SpeedCure XKm (#CAS 1539267-56-5, manufactured by SARTOMER).

Furthermore, in the general formula (1), R ₁ , R ₂ , R ₄ are methyl groups, R ₃ and Y ₁ are hydrogen atoms, Y ₃ is a phenyl group, and Y2 is represented by the general formula (3). R ₁₀ , R ₁₁ , and R ₁₃ are methyl groups, R ₁₂ and Y ₁₁ are hydrogen atoms, Y ₃₃ is a phenyl group, and R ₁₄ and R ₁₅ are (poly)oxyalkylene groups having 2 carbon atoms. A commercially available product is Omnipol TP (#CAS 1834525-17-5, manufactured by IGM Resins B.V.).
These acylphosphine oxide compounds may be used alone or in combination of two or more.

In general formula (3), Y ₁₁ each independently represents the same group as Y ₁ in general formula (1),
Y ₃₃ in general formula (3) each independently represents the same group as Y ₃ in general formula (1),
R ₁₄ and R ₁₅ in general formula (3) each independently represent an alkylene group having 1 to 6 carbon atoms or a (poly)oxyalkylene group having 1 to 6 carbon atoms,
R ₁ to R ₁₃ in the general formulas (1), (2), and (3) each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

As the photopolymerization initiator (2) used in the active energy ray-curable offset ink of the present invention, a benzophenone compound, a thioxanthone compound, and/or a ketocoumarin compound are used.

Examples of the benzophenone compounds include 4,4'-dialkylaminobenzophenones such as 4,4'-bis-(dimethylamino)benzophenone and 4,4'-bis-(diethylamino)benzophenone, and 4-benzoyl-4'-methyl. Examples include diphenyl sulfide and 4-methylbenzophenone. Among these, 4,4'-bis-(diethylamino)benzophenone is preferred from the viewpoint of safety. These benzophenone compounds may be used alone or in combination of two or more.

The thioxanthone compounds include 2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, 2-isopropylthioxanthone, 4-diisopropylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diisopropylthioxanthone, -dichlorothioxanthone, 2-chlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2-hydroxy-3-(3,4-dimethyl-9-oxo-9Hthioxanthone-2-yloxy-N,N,N-trimethyl- 1-propanamine hydrochloride and the like, preferably 2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2-chlorothioxanthone, -isopropylthioxanthone.These thioxanthone compounds may be used alone or in combination of two or more.

Examples of the ketocoumarin compounds include 3-benzoylcoumarin, 3-(4-methoxybenzoyl)coumarin, 3-benzoyl-7-methoxycoumarin, 3-(4-methoxybenzoyl)7-methoxy-3-coumarin, and 3-acetyl-coumarin. Examples include 7-dimethylaminocoumarin, 3-benzoyl-7-dimethylaminocoumarin, 3,3'-coumarinoketone, and 3,3'-bis(7-diethylaminocoumarino)ketone. These ketocoumarin compounds may be used alone or in combination of two or more.

Further, photopolymerization initiators other than the photopolymerization initiators (1) and (2) used in the active energy ray-curable offset ink of the present invention include hydroxyacetophenone compounds, benzyl dimethyl ketal compounds, and the like.

Examples of the hydroxyacetophenone compound include ethyl phenyl(2,4,6-trimethylbenzoyl)phosphinate, 1-hydroxy-cyclohexylphenyl ketone (eg, Omnirad 184, manufactured by IGM Resins B.V.), 1-[4 -(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl) -benzyl]phenyl}-2-methyl-propan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and the like. These hydroxyacetophenone compounds may be used alone or in combination of two or more.

Furthermore, a benzyl dimethyl ketal compound may be used as the photopolymerization initiator (3). Examples of the benzyl dimethyl ketal compound include 2,2-dimethoxy-2-phenylacetophenone (Omnirad 651, manufactured by IGM Resins B.V.).

The content of the photopolymerization initiator using the α-aminoalkylphenone compound is preferably in the range of 2 to 10% by mass based on the total amount of each ink. If it is 2% by mass or more, curability can be obtained, and if it is 10% by mass or more, the precipitation of the initiator and the odor of the cured product become noticeable. Further, the content of the photopolymerization initiator using the acylphosphine oxide compound is preferably in the range of 4 to 20% by mass based on the total amount of the ink. If it is 4% by mass or more, curability can be obtained, and if it is 20% by mass or more, it tends to be saturated and dissolved in the acrylate monomer, impairing fluidity.
The content of the photopolymerization initiator using the benzophenone compound, the thioxanthone compound, and the ketocoumarin compound is preferably in the range of 2 to 8% by mass of the total amount of the ink. If it is 2% by mass or more, curability can be obtained, and if it is 8% by mass or more, it will be saturated and dissolved in the acrylate monomer, impairing fluidity.
The content of the photopolymerization initiator using the hydroxyacetophenone compound and the benzyl dimethyl ketal compound is preferably in the range of 2 to 8% by mass of the total amount of the ink. If it is 2% by mass or more, curability can be obtained, and if it is 8% by mass or more, it will be saturated and dissolved in the acrylate monomer, impairing fluidity.
Further, from the viewpoint of achieving both excellent curability and excellent fluidity when using various compounds in combination, the amounts of both compounds added are preferably within this range.

Furthermore, the active energy ray-curable offset ink of the present invention must contain (4) a compound having an ethylenic double bond.

Examples of the compound having an ethylenic double bond include (meth)acrylic group-containing compounds and additives.
Examples of monofunctional monomers that are (meth)acrylic group-containing compounds include ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, and lauryl (meth)acrylate. , tridecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, isoamyl (meth)acrylate, isodecyl (meth)acrylate, isostearyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, Methoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, nonylphenoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, glycidyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, diethylaminoethyl (meth)acrylate, nonylphenoxyethyltetrahydrofurfuryl (meth)acrylate ) acrylate, caprolactone-modified tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and the like.

Examples of monomers having two or more functionalities include 1,4-butanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, Neopentyl glycol di(meth)acrylate, 2-methyl-1,8-octanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, tricyclodecane dimethanol 2 such as di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, etc. Di(meth)acrylate of alcohol, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, di(meth)acrylate of tris(2-hydroxyethyl)isocyanurate, 4 mol or more per mol of neopentyl glycol Di(meth)acrylate of diol obtained by adding ethylene oxide or propylene oxide to 1 mole of bisphenol A, di(meth)acrylate of diol obtained by adding 2 moles of ethylene oxide or propylene oxide to 1 mole of bisphenol A, trimethylolpropanetri (meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol polyhydric alcohol poly(meth)acrylate, etc. (Meth)acrylate, tri(meth)acrylate of a triol obtained by adding 3 moles or more of ethylene oxide or propylene oxide to 1 mole of glycerin, or tri(meth)acrylate of a triol obtained by adding 3 moles or more of ethylene oxide or propylene oxide to 1 mole of trimethylolpropane. poly(meth)acrylates of polyoxyalkylene polyols, such as di- or tri(meth)acrylates of triols obtained by adding 4 moles or more of ethylene oxide or propylene oxide to 1 mole of bisphenol A; Examples include acrylate.

Furthermore, the (meth)acrylic group-containing compound may be a polymerizable oligomer. Examples of polymerizable oligomers include amine-modified acrylates such as amine-modified polyether acrylate, amine-modified epoxy acrylate, amine-modified aliphatic acrylate, amine-modified polyester acrylate, and amino (meth)acrylate, polyester (meth)acrylate, and polyether (meth)acrylate. Examples include acrylate, polyolefin (meth)acrylate, polystyrene (meth)acrylate, epoxy (meth)acrylate, urethane (meth)acrylate, and the like.

The total amount of compounds having ethylenic double bonds is preferably in the range of 10 to 60% by mass, more preferably 10 to 40% by mass, and even more preferably in the range of 10 to 25% by mass, based on the total amount of the ink composition. . Further, from the viewpoint of achieving both excellent curability and excellent fluidity when using various compounds in combination, the amounts of both compounds added are preferably within this range.

<Stabilizer>
The active energy ray-curable offset printing ink of the present invention preferably contains a dimethyldithiocarbamate copper complex. Containing this stabilizer makes it possible to capture free radicals generated by heat, metal ions, auto-oxidation, etc. in the absence of light, and prevents unintended polymerization reactions in active energy ray-curable offset printing inks. This makes it possible to maintain the ink viscosity within an appropriate range for a long period of time. The dimethyldithiocarbamate copper complex is preferably contained in an amount of 0.01 to 0.3% by mass based on the total amount of the ink.

(Dialkyldithiocarbamate copper complex)
Examples of the dialkyldithiocarbamate copper complex used in the present invention include copper dimethyldithiocarbamate, copper diethyldithiocarbamate, copper dibutyldithiocarbamate, and the like. Among them, copper dimethyldithiocarbamate is preferred.

(nitrosamine compound)
In addition to the dialkyldithiocarbamate copper complex, the active energy ray-curable offset printing ink of the present invention may further contain a nitrosamine compound as a stabilizer. By using the nitrosamine compound in combination, it becomes possible to maintain the viscosity of the ink within an appropriate range for a long period of time. Examples of the nitrosamine compound that can be used in the present invention include N-nitrosophenylhydroxylamine aluminum salt, and a commercially available product is n-nitrosophenylhydroxylamine aluminum salt (Q-1301, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.). can be mentioned.

At least one stabilizer used in the present invention is preferably contained in an amount of 0.01 to 0.30% by mass based on the total amount of the ink, and within this range, the active energy ray-curable offset printing ink of the present invention This is preferable because it does not reduce the curing performance of. Further, it is more preferable that the stabilizer is contained in an amount of 0.03 to 0.20% by mass based on the total amount of the ink.

Furthermore, extender pigments may be used in the active energy ray-curable offset printing ink of the present invention. Inorganic fine particles can be used as the extender pigment. Inorganic fine particles include inorganic coloring pigments such as titanium oxide, graphite, and zinc white; carbonate lime powder, precipitated calcium carbonate, precipitated barium sulfate, gypsum, clay (ChinaClay), silica, diatomaceous earth, talc, kaolin, alumina white, Examples include inorganic pigments such as barium sulfate, aluminum stearate, calcium stearate, magnesium carbonate, barite powder, abrasive powder, etc., silicone, and glass beads. These inorganic fine particles have the effect of adjusting ink fluidity, preventing misting, and preventing penetration into printing substrates such as paper, as well as suppressing paper peeling problems that occur when printing under low-temperature conditions such as winter or when printing at high speeds. You can add the effect of
Particularly when the base material is a paper material, talc, magnesium carbonate, and silica are preferred from the viewpoint of suppressing "paper peeling", and talc and magnesium carbonate are particularly preferred from the viewpoint of maintaining the fluidity of the composition.

The talc, magnesium carbonate, and silica may be used alone or in combination of two or more. When the talc is used, its content is preferably in the range of 1 to 6% by mass of the total amount of the ink, and when magnesium carbonate is used, the content is preferably in the range of 1 to 10% by mass of the total amount of the ink. When used, the content is preferably 0.1 to 5% by mass based on the total amount of the ink.

Furthermore, since the active energy ray-curable offset ink of the present invention can improve the curability of the cured coating film of the ink, a photosensitizer may be further added to improve the curability, if necessary. can.

Examples of the photosensitizer include amine compounds such as aliphatic amines and aromatic amines, urea compounds such as o-tolylthiourea, sulfur compounds such as sodium diethyldithiophosphate, and s-benzylisothiuronium-p-toluenesulfonate. Examples include compounds. The amount of these photosensitizers to be used is preferably in the range of 1 to 20% by mass based on the total amount of the active energy ray-curable ink of the present invention in order to obtain a good effect of improving curability.

The active energy ray-curable offset ink of the present invention may further contain antioxidants, polymerization inhibitors, silicone additives, waxes, pigments, dyes, etc., if necessary.

Examples of the antioxidant include hindered phenol antioxidants, hindered amine antioxidants, organic sulfur antioxidants, phosphate ester antioxidants, and the like. These antioxidants can be used alone or in combination of two or more.

Examples of the silicone additive include dimethylpolysiloxane, methylphenylpolysiloxane, cyclic dimethylpolysiloxane, methylhydrogenpolysiloxane, polyether-modified dimethylpolysiloxane copolymer, polyester-modified dimethylpolysiloxane copolymer, and fluorine-modified copolymer. Dimethylpolysiloxane copolymers, polyorganosiloxanes with alkyl groups or phenyl groups such as amino-modified dimethylpolysiloxane copolymers, polydimethylsiloxanes with polyether-modified acrylic groups, polydimethylsiloxanes with polyester-modified acrylic groups, etc. Can be mentioned. These silicon-based additives can be used alone or in combination of two or more.

In the active energy ray-curable offset ink of the present invention, wax can be added for the purpose of improving curability. The waxes include waxes such as paraffin wax, carnauba wax, beeswax, microcrystalline wax, polyethylene wax, oxidized polyethylene wax, polytetrafluoroethylene wax, and amide wax, and waxes containing 8 to 8 carbon atoms such as coconut oil fatty acid and soybean oil fatty acid. Examples include fatty acids in the range of about 18.

In the active energy ray-curable offset ink of the present invention, known and commonly used inorganic pigments and organic pigments can be used.

Examples of the inorganic pigment include iron oxide, carbon black produced by a known method such as a contact method, a furnace method, and a thermal method.
For example, Raben 14, Raben 450, Raben 860 Ultra, Raben 1035, Raben 1040, Raben 1060 Ultra, Raben 1080 Ultra, Raben 1180, Raben 1255 (all manufactured by Birla), Regal 250R, Regal 400R, Regal 330R, Regal 660R, Mogul L (all manufactured by Cabot), MA7, MA8, MA11 (all manufactured by Mitsubishi Chemical), etc. These may be used alone or in combination of two or more as appropriate. good.

Examples of the organic pigments include quinacridone pigments, quinacridonequinone pigments, dioxazine pigments, phthalocyanine pigments, anthrapyrimidine pigments, anthanthrone pigments, indanthrone pigments, flavanthrone pigments, perylene pigments, diketopyrrolopyrrole pigments, perinone pigments, Examples include quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, and azo pigments. These pigments can be used alone or in combination of two or more.

Specific examples of pigments used in yellow ink include C.I. I. Pigment Yellow 1, 2, 12, 13, 14, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 109, 110, 114, 120, 128, 129, 138, 150, 151, 154, 155, 174, 180, 185 and the like.

Further, specific examples of pigments used in magenta ink include C.I. I. Pigment Red 5, 7, 12, 48 (Ca), 48 (Mn), 57 (Ca), 57:1, 112, 122, 123, 146, 168, 176, 184, 185, 202, 209, 269, etc. C. I. Pigment Violet 19 and the like.

Further, specific examples of pigments used in cyan ink include C.I. I. Pigment Blue 1, 2, 3, 15, 15:3, 15:4, 16, 22, 60, 63, 66 and the like.

Examples of dyes include azo dyes such as monoazo and disazo, metal complex dyes, naphthol dyes, anthraquinone dyes, indigo dyes, carbonium dyes, quinoimine dyes, cyanine dyes, quinoline dyes, nitro dyes, nitroso dyes, benzoquinone dyes, and naphthoquinone. Examples include dyes, naphthalimide dyes, perinone dyes, phthalocyanine dyes, and triallylmethane dyes. These dyes can be used alone or in combination of two or more.

(resin)
As the resin, various publicly known binder resins can be used. The binder resin mentioned here refers to resins in general that have appropriate pigment affinity and dispersibility and rheological properties required for printing inks. Examples of non-reactive resins include diallyl phthalate resin, epoxy Resin, polyurethane resin, polyester resin, petroleum resin, rosin ester resin, poly(meth)acrylate ester, cellulose derivative, vinyl chloride-vinyl acetate copolymer, polyamide resin, polyvinyl acetal resin, butadiene-acrylonitrile copolymer, etc. In addition, epoxy acrylate compounds, urethane acrylate compounds, polyester acrylate compounds, etc. having at least one polymerizable group in the molecule can also be used, and these binder resins can be used alone. , any one or more of them may be used in combination.

The active energy ray-curable offset ink of the present invention can be made into a cured coating film by irradiating active energy rays after printing on a substrate.

Examples of the active energy ray include ionizing radiation such as ultraviolet rays, electron beams, α rays, β rays, and γ rays. Further, when ultraviolet rays are used as the active energy rays, in order to efficiently perform the curing reaction by ultraviolet rays, the irradiation may be performed in an inert gas atmosphere such as nitrogen gas, or in an air atmosphere.

As the source of the ultraviolet light, an ultraviolet lamp is generally used from the viewpoint of practicality and economy. Specifically, germicidal lamps, ultraviolet fluorescent lamps, high-pressure mercury lamps for copying, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, electrodeless lamps, carbon arcs, xenon lamps, gallium lamps, and metal halides. Examples include lamps, sunlight, ultraviolet light emitting diodes (UV-LEDs), and the like.

In particular, in the active energy ray-curable offset ink of the present invention, the ink is difficult to gel by appropriately using the photopolymerization initiators (1) to (3) and (4) a compound having an ethylenic double bond. Not only conventional metal halide lamps and high-pressure mercury lamps, but also ozone-less metal halide lamps that do not generate ozone, light emitting diodes, and UV-LED lamps can maintain excellent curing properties, excellent surface curing properties, internal curing properties, and adhesion. can.

There are no particular limitations on the printing substrate used in the active energy ray-curable offset ink of the present invention, and examples include catalogs, posters, leaflets, CD jackets, direct mail, pamphlets, and packages for cosmetics, beverages, pharmaceuticals, toys, equipment, etc. Can be used for high-quality paper, coated paper, art paper, imitation paper, thin paper, cardboard, etc. used for printing, various synthetic papers, etc., as well as polyester resin, acrylic resin, vinyl chloride resin, vinylidene chloride resin, polyvinyl alcohol. , films or sheets of polyethylene, polypropylene, polyacrylonitrile, ethylene vinyl acetate copolymer, ethylene vinyl alcohol copolymer, ethylene methacrylic acid copolymer, nylon, polylactic acid, polycarbonate, cellophane, aluminum foil, and other conventional printing materials. It can be used for various base materials used as base materials.
Among these, it is preferable that the printing equipment serving as the printing material is paper with a water content of 5 to 300 grams per square meter.
Further, it may be used for other base materials such as metal base materials, glass base materials, paper base materials, wood base materials, and fibrous base materials.

The production of the active energy ray curable offset ink described in the present invention involves blending the above-mentioned compound having an ethylenic double bond, a photopolymerization initiator, other additives, etc. in the same way as conventional active energy ray curable offset inks. It is produced by stirring and mixing using a mixer or the like, and kneading using a dispersing machine such as a three-roll mill or a bead mill.

Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples.

[Production method of DAP-A varnish]
Diaryl phthalate resin (Daiso DAP A, manufactured by Osaka Soda Co., Ltd.) with a solid content of 33.33% by mass and MIRAMER M600 dipentaerythritol hexaacrylate (manufactured by MIWON) 66.67% by mass were sufficiently dissolved and stirred at 90°C to form DAP varnish. was created.

[Production method of active energy ray-curable offset printing ink]
Active energy ray curable offset printing was performed by kneading the active energy ray curable offset printing inks of Examples 1 to 13 and Comparative Examples 1 to 12 in a three-roll mill according to the formulations listed in Tables 1 to 4. Got the ink. In addition, a blank column in the table means that it is not blended, and the numerical value in the table is mass %.

The produced active energy ray-curable offset printing inks were evaluated for gelation speed, curability, and adhesion.

(Evaluation item 1: gelation rate)
The gelation rate was measured by using an automatic curing time measurement device "Madoka" manufactured by Cyber Co., Ltd., and measuring the time (in seconds) from the start of stirring until the torque increased by 20%. The shorter the number of seconds, the easier it is to gel.
The amount of active energy ray-curable offset ink used for one measurement was 0.2 ml, and the stirring conditions were a rotation speed of 300 rpm and a revolution speed of 120 rpm.
After confirming that the temperature was stabilized at 80°C for 5 minutes, the temperature was increased to 250°C in 1000 seconds.
Further, the gap value between the bottom of the ink container and the tip of the stirrer was set to 0.1 mm. The evaluation criteria were the following four levels.
(Evaluation criteria)
4: 840 seconds or more and less than 1000 seconds 3: 810 seconds or more and less than 840 seconds 2: 750 seconds or more and less than 810 seconds 1: Less than 750 seconds

(Evaluation item 2: Curability)
Regarding curability, 0.125 mL of the ink of Examples and Comparative Examples was used on OK Tack (polyethylene terephthalate tack film) UVPET Toumei 25FL-S manufactured by Oji Tack Co., Ltd., which is easy to evaluate because the ink does not penetrate into the base material. , was printed using a simple color spreader (RI Tester, manufactured by Toyoei Seiko Co., Ltd.). This printed material is placed on the conveyor using a UV irradiation device (manufactured by I-Graphics Co., Ltd.) equipped with a water-cooled UV-LED (center emission wavelength 385 nm ± 5 nm UV-LED output 100%) and a belt conveyor. The printed matter was irradiated with ultraviolet light (UV) by passing directly under the LED (irradiation distance 9 cm) at a conveyor speed in the range of 10 m/min to 35 m/min to harden and dry the ink film.
The solid surface of the produced printed matter was rubbed with high-quality paper, and the curing property was evaluated at the conveyor speed at which the ink stopped adhering, according to the following five-grade evaluation criteria.
(Evaluation criteria)
5: 30 m/min or more and less than 35 m/min.
4: 25 m/min or more and less than 30 m/min.
3: 20 m/min or more and less than 25 m/min.
2: 15 m/min or more and less than 20 m/min.
1: 10 m/min or more and less than 15 m/min.

(Evaluation item 3: Adhesion)
Printing was carried out on the following four types of paper using a simple color spreader (RI tester, manufactured by Toyoei Seiko Co., Ltd.) using 0.125 mL of the inks of Examples and Comparative Examples. This printed material is placed on the conveyor using a UV irradiation device (manufactured by I-Graphics Co., Ltd.) equipped with a water-cooled UV-LED (center emission wavelength 385 nm ± 5 nm UV-LED output 100%) and a belt conveyor. The printed material was irradiated with ultraviolet (UV) light by passing directly under the LED (irradiation distance 9 cm) at a conveyor speed of 10 m/min to cure and dry the ink film.
The water content of each paper was measured and calculated according to the following procedure.
The test device takes measurements by filling 100 ml of tap water into a volume formed by a test piece paper at the top and bottom of a cylindrical metal. A test piece paper whose mass has been measured in advance is placed and fixed on the upper (50 cm ² ) and lower (50 cm ² ) bottom of a cylindrical metal (inner volume: 100 cm ³ ). Polyethylene laminate paper was used as an underlay to prevent water from draining through the test piece paper. After filling the test device with 100 ml of tap water, let it stand for 60 seconds to allow the top and bottom of the test piece paper to absorb the tap water.
Next, the tap water filled in the volume is removed, high-quality paper is applied to the test piece paper to remove excess water, and the mass of the test piece paper that has absorbed water is measured.
The measurement was carried out twice and the average value was taken as the ^average value, and the water content (g/ m ² ) was calculated and taken as the water content (g/m ² ) of the paper.
The paper types and water content are as follows.
・UF coat (Oji Paper coated cardboard, weight 23.5Kg, moisture content 93.8g/m ² )
・Shiraoi (high-quality paper manufactured by Nippon Paper Industries, weight 70.5 kg, moisture content 167.0 g/m ² )
・Yonago OK Top Coat Plus (manufactured by Oji Paper, weight 57.5 kg, moisture content 104.9 g/m ² )
・New Age (Oji Paper matte coated paper, weight 44.5Kg, moisture content 50.8g/m ² )
A peel test was performed on the solid surface of the produced printed matter using a cellophane tape (CT405AP-18) manufactured by Nichiban Co., Ltd. with respect to the base material of the cured ink film, and visually evaluated according to the following three-level evaluation criteria.
(Evaluation criteria)
○: No peeling spots were observed.
Δ: Peeling is observed in less than 50% of the entire area.
×: Peeling is observed in 50% or more of the entire area.

Tables 1 to 4 show the formulations and evaluation results of each active energy ray-curable offset printing ink.

The abbreviations in the table are as follows.
・FASTOGEN BLUE FA5375: Pigment Blue 15:3 indigo pigment (manufactured by DIC Corporation)
・Miramer M600: Dipentaerythritol hexaacrylate (manufactured by Miwon)
・Miramer M3130: Ethylene oxide modified (3 mol) trimethylolpropane triacrylate (manufactured by Miwon)
・Omnirad 907: 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (manufactured by IGM Resins B.V.)
・Omnirad 379: 2-dimethylamino-2-(4-methyl-benzoyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one (manufactured by IGM Resins B.V.)
・Omnirad TPO-L: 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (manufactured by IGM Resins B.V.)
・Omnirad EMK: 4,4′-bis-(diethylamino)benzophenone (manufactured by IGM Resins B.V.)
・Omnirad DETX: 2-methyl-[4-(methylthio)phenyl]-2-morpholino-1-propane (manufactured by IGM Resins B.V.)
・Omnirad 184: 1-hydroxycyclohexylphenyl ketone (manufactured by IGM Resins B.V.)
・Sunseller TT-CU: Copper dimethyldithiocarbamate (manufactured by Sanshin Chemical Industry Co., Ltd.)
・Q-1301: n-nitrosophinyl hydroxylamine aluminum salt (Fuji Film Wako Pure Chemical Industries, Ltd.)
・ADEKA STAB 7RD: 4-Hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical (TMPOL) (manufactured by ADEKA Co., Ltd.)
・Methylhydroquinone: Manufactured by Tsubakimoto Kasei Co., Ltd.

The active energy ray-curable offset ink of the present invention can suppress gelation while having both curability and adhesion.

The abbreviations in the table are as follows.
・FASTOGEN BLUE FA5375: Pigment Blue 15:3 indigo pigment (manufactured by DIC Corporation)
・Miramer M600: Dipentaerythritol hexaacrylate (manufactured by Miwon)
・Miramer M3130: Ethylene oxide modified (3 mol) trimethylolpropane triacrylate (manufactured by Miwon)
・Omnirad 907: 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (manufactured by IGM Resins B.V.)
・Omnirad 379: 2-dimethylamino-2-(4-methyl-benzoyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one (manufactured by IGM Resins B.V.)
・Omnirad TPO-L: Ethylphenyl (2,4,6-trimethylbenzoyl)phosphinate (manufactured by IGM Resins B.V.)
・Omnirad EMK: 4,4′-bis-(diethylamino)benzophenone (manufactured by IGM Resins B.V.)
・Omnirad DETX: 2,4-diethyl-9H-thioxanthene-9-one (manufactured by IGM Resins B.V.)
・Omnirad 184: 1-hydroxycyclohexylphenyl ketone (manufactured by IGM Resins B.V.)
・Sunseller TT-CU: Copper dimethyldithiocarbamate (manufactured by Sanshin Chemical Industry Co., Ltd.)
・Q-1301: n-nitrosophinyl hydroxylamine aluminum salt (Fuji Film Wako Pure Chemical Industries, Ltd.)
・ADEKA STAB 7RD: 4-Hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical (TMPOL) (manufactured by ADEKA Co., Ltd.)
・Methylhydroquinone: Manufactured by Tsubakimoto Kasei Co., Ltd.

Claims (9)

An active energy ray-curable offset printing ink containing a photopolymerization initiator and a compound having an ethylenic double bond,
An active energy ray-curable offset printing ink, characterized in that the gelation rate until the torque increases by 20% according to the ink viscosity measurement method is in the range of 750 seconds to 1000 seconds.
The active energy ray-curable offset printing ink is
(1) a photopolymerization initiator (1) that is an α-aminoalkylphenone compound and/or an acylphosphine oxide compound;
(2) a photopolymerization initiator (2) which is a benzophenone compound, a thioxanthone compound, and/or a ketocoumarin compound;
(3) a stabilizer that is a dimethyldithiocarbamate copper complex;
(4) The active energy ray-curable offset printing ink according to claim 1, which contains a compound having an ethylenic double bond. The α-aminoalkylphenone compound is 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-dimethylamino-2-(4-methyl-benzyl)-1-( 4-morpholin-4-yl-phenyl)-butan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethyl Amino-1-(4-piperidinylphenyl)-1-butanone, 1-(biphenyl-4-yl)-2-methyl-2-morpholinopropan-1-one, 1-(4-methoxyphenyl)- 2-Methyl-2-morpholin-4-yl-propan-1-one, polyethylene glycol (200) di(β-4[4-(2-dimethylamino-2-benzyl)butanonylphenyl]piperazine propionate The active energy ray-curable offset printing ink according to claim 1. The active energy ray-curable offset printing ink according to claim 1, wherein the acylphosphine oxide compound is a compound represented by general formula (1).

In general formula (1),
Y ₁ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a structural moiety represented by general formula (2),
Y ₂ is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a (poly)alkoxyalkyl group having 1 to 6 carbon atoms (the alkoxyalkyl group is an alkyl group having 1 to 6 carbon atoms). represents a structural moiety represented by alkoxyalkyl group), phenyl group, or general formula (3),
Y ₃ represents a phenyl group or a group represented by general formula (2),

In general formula (3), Y ₁₁ each independently represents the same group as Y ₁ in general formula (1),
Y ₃₃ in general formula (3) each independently represents the same group as Y ₃ in general formula (1),
R ₁₄ and R ₁₅ in general formula (3) each independently represent an alkylene group having 1 to 6 carbon atoms or a (poly)oxyalkylene group having 1 to 6 carbon atoms,
R ₁ to R ₁₃ in the general formulas (1), (2), and (3) each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
The benzophenone compound is selected from the group consisting of 4,4'-bis-(dimethylamino)benzophenone, 4,4'-bis-(diethylamino)benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and 4-methylbenzophenone. 2. The active energy ray-curable offset printing ink according to claim 1, which is at least one type of active energy ray-curable offset printing ink. The active energy ray-curable offset printing ink according to claim 1, which contains the dimethyldithiocarbamate copper complex and the nitrosamine compound as stabilizers in an amount of 0.01 to 0.30% by mass based on the total amount of the ink. The active energy ray-curable offset printing ink according to claim 1, wherein the compound having an ethylenic double bond is a compound having two or more ethylenic double bonds. A printed matter comprising the steps of: printing the active energy ray-curable offset printing ink according to any one of claims 1 to 7 on a printing substrate; and curing the ink printed with the active energy ray. manufacturing method. 9. The method for producing printed matter according to claim 8, wherein the printed matter is paper having a moisture content of 5 to 300 grams per square meter.